Glaucoma is the leading cause of irreversible blindness worldwide.

Open angle glaucoma is a leading cause of irreversible blindness in the US and the world affecting about 2.7 million American and 57.5 million patients worldwide and costing the US economy $2.86 billion annually. 

The prevalence and severity of glaucoma are even higher in African Americans and Hispanics. About 300,000 new patients are diagnosed with glaucoma in the US every year. The cost to the US economy for medical care, disability, and low vision rehabilitation is almost $3 billion annually. Furthermore, the prevalence of glaucoma is expected to increase dramatically as the population ages. Annual medical costs are projected to top $17 billion by 2050. OAG is dependent on IOP, with high IOP being a causal risk factor for the disease. Approximately 7–8% of individuals above age 40 have elevated IOP. 

Since IOP is the only modifiable risk factor for OAG, IOP lowering is the only effective way of preventing visual disability from OAG. In OAG, malfunction or pathology of the outflow tissues leads to increased outflow resistance and IOP elevation. Most eyedrop medications used to lower IOP act by either reducing the production of aqueous humor (β-adrenergic antagonists, α2-adrenergic agonists, carbonic anhydrase inhibitors) or increasing uveoscleral outflow (which accounts for a small portion of the total outflow of aqueous humor in humans). 

Since uveoscleral outflow and aqueous humor production (flow) are not different between glaucoma patients and healthy controls, only Rho-kinase inhibitors and parasympathomimetic agents primarily act at the site of pathology, namely the TM. Both of these medication classes have significant side effects. Laser therapy (trabeculoplasty) can be used to lower IOP but its effect is modest and does not last very long. For patients with uncontrolled OAG, incisional surgery may be an option but is highly invasive, can cause significant complications, and typically fails over time.